• LUKS Hard Drive Encryption on Linux Mint Ubuntu Debian etc how to mount encrypted hard drive


    The key thing here is to know the actual partition that is encrypted. Often in Linux Mint's installer that ends up being partition 5 or /dev/sda5 sudo cryptsetup luksOpen /dev/sda5 anynamehere You will then be prompted for your irrecoverable passphrase: Enter passphrase for /dev/sda5: If all goes well it won't say anything further. If it says ""No key available with this passphr........
  • SSH error cannot Forward or Listen "bind: Cannot assign requested address"


    debug1: Local connections to LOCALHOST:18006 forwarded to remote address 192.168.1.93:8006 debug1: Local forwarding listening on 127.0.0.1 port 18006. debug1: channel 0: new [port listener] debug1: Local forwarding listening on ::1 port 18006. bind: Cannot assign requested address What we are seeing is that we can't listen on an IPV6 address of ::1. We need to tell SSH to stop using IPV6 so we'll edit ssh_config to take care of this issue........
  • bind named error solutions named[2169]: error (no valid DS) resolving / error (broken trust chain) resolving / : error (no valid RRSIG) resolving 'com/DS/IN':


    Below are the common errors you'll get with named AKA bind if your time is incorrect. The simplest solution is to install and run ntpd to correct your system's time (install ntpd if it is not installed) systemctl start ntpd systemctl enable ntpd Dec 20 13:36:16 hostingbox named[2169]: error (no valid DS) resolving 'develop.waxrain.com/A/IN': 14.215.150.17#53........
  • Linux named / bind how to dump, view and clear the cache!


    Do you hate it when your ISPhas old cached records because of a high TTLon the DNS record of the relevant domain? In plain English this means you often can't connect to a site or service because your ISP's DNS servers haven't gotten word of the new IP address (probably because they haven't checked). There are also some that are notorious for ignoring TTL and not updating records for days! But if you are lucky and smart enough to have your own Linux based DNS se........
  • systemd management using systemctl and journalctl to check systemd logs


    systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system. The key commands or arguments you will use with systemctl are the following: Unit Commands: list-units [PATTERN...] List loaded units &nbs........
  • Postfix How To Change Sending IP Address To Specific IP Binding or Interface


    Ithought I'd post this becuase there is some bad information out there. Some guides tell you to edit /etc/postfix/master.cf (-o smtp_bind_address=) but this doesn't work. The same guide also says if you don't change it there you end up changing the listening IP/bind interface which is also not true. Here is a simple and effective way to change Postfix's sending/binding/outgoing IP address (very important for reverse DNS and so mail servers don't block you)........
  • VSphere InternalServerError - Error When Adding Permissions


    InternalServerError (com.vmware.vapi.std.errors.internal_server_error) => { messages = [LocalizableMessage (com.vmware.vapi.std.localizable_message) => { id = vapi.bindings.method.impl.unexpected, defaultMessage = Provider method implementation threw unexpected exception: com.vmware.vapi.std.errors.InternalServerError, args = [com.vmware.vapi.std.errors.InternalServerError] }], data = } I was getting the........
  • named [FAILED] - zone 1.168.192.in-addr.arpa/IN: not loaded due to errors. - bind error solution


    Centos when copying old files and restarting it seems load everything fine and then says [FAILED] with no log or other message. service restart named named [FAILED] Check more thoroughly you may have missed the error if you have lots of zones! service named restart|grep error zone 1.168.192.in-addr.arpa/IN: not loaded due to errors. zone 2.168.192.in-addr.arpa/IN: no........
  • samba how to listen on specific IP only


    This is useful for security purposes especially on a server which may have a public IP assigned to it but has a second NIC for the LAN. Here is how you edit smb.conf: [global] interfaces = 192.168.1.50 bind interfaces only = yes As you can see above it will only listen on 192.168.1.50 and remind to keep the "bind interfaces only"option.........
  • How To Secure Samba NMBD/SMBD to bind to a specific IP address


    By default Samba SMB/NMB listen on ANY and ALLIPs on your system by binding to 0.0.0.0. Obviously this is a huge security risk if you have a public facing server with both internal and external access. Usually when a system administrator sets up a samba server their intention is just to share with a LAN. To do this you need to the following options under the [global] section in smb.conf bind interfaces only = yes interfaces = 192........
  • Wine uninstalled broken on Linux Mint


    Solution: Aptitude is very smart and fixed the issues it was because of nvidia cuda and opencl and nothing else suggested or hinted this using apt sudo aptitude install wine The following NEW packages will be installed: ocl-icd-libopencl1{ab} ocl-icd-libopencl1:i386{ab} wine wine1.6 wine1.6-amd64{a} wine1.6-i386:i386{a} The following packages will be REMOVED:........
  • Migrate Centos 7 from Single HDD to mdadm RAID 10 array:


    Done on Centos 7.3 very important as clearly based on older guides it was a lot easier and more simpler! Hint do not use grub2-install! One huge caveat if you are an oldschool user or sysadmin who has avoided UEFIbooting The normal way will not work here if your Centos was using UEFI. Newer systems use it by default. The easiest way to check is to do an fdisk -l if your sy........
  • What happens when you unplug 1 or more devices from an mdadm RAID array to simulate a failure in Linux Ubuntu/Centos/Debian?


    In short the two drives in the array were /dev/sdd and /dev/sde. The kernel sees they were unplugged and have gone down as you can see below. mdadm caught the first one being unplugged /dev/sde and disabled the missing drive. However when the final drive that was part of the array is unplugged it didn't notice at all. Instead it complains about an IO error later for drives that the kernel knows do not exist anymore. [45817.162728] ata4: exception........
  • Migrating from Linux Mint 17.2 mdadm RAID array to a new one (because I upgraded to larger drives).


    1.) Replicate the number of partitions in your new drives. gdisk /dev/sda gdisk /dev/sdb I created 3 partitions of the same same size. partition #1: +1G (/boot) partition #2: +60G (swap) partition #3: rest of it (/) #note if you are using GPT/gdisk you need to create separate a partition at least 1MB in size (in my case I would a 4th partition and mark it type ef02).........
  • mdadm frozen and doesn't realize array is dead/missing failed due to unplugged drives


    This was a surprising bug but I unplugged all drives for an array md127. At first it was just 1 drive and mdadm seemed to notice this. I unplugged the second drive taking the array offline but mdadm did not realize it was offline and still showed a non-existent disk as being part of it. This created problems trying to unmount it or even to stop this array with mdadm freezing. As for how to fix it I can only think of making sure you are not in a mounted path of........
  • bind/named rndc: connect failed: 127.0.0.1#953: connection refused (solution)


    service named status rndc: connect failed: 127.0.0.1#953: connection refused named (pid 10557) is running... Check /var/log/messages: Jan 4 17:06:22 storagebox named[10753]: none:0: open: /etc/rndc.key: permission denied Jan 4 17:06:22 storagebox named[10753]: couldn't add command channel 127.0.0.1#953: permission denied Jan 4 17:06:22 storagebox named[10753]: non........
  • Centos 6 how to guide convert LVM non-RAID into mdadm 1/10 RAID array live without reinstalling


    Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason. Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to? In some cases on a remote system you can't easily reinstall without physical or KVM access. So in this case you add a second physical or disk or already ha........
  • mount -o bind permanent in /etc/fstab howto


    mount -o bind /somedir /anotherdir In /etc/fstab /somedir /anotherdir none bind 0 0........
  • How To Install Linux Mint 17.2 on mdadm RAID with a separate boot partition


    Iwas surprised to see that Linux Mint at the latest 17.2 version still has NO mdadm installer option, and worse the installer will not be able to create a proper booting environment even when you do install it. How to setup mdadm in Linux mint LiveCD sudo su apt-get install mdadm # partition as you need and then create your mdadm devices # create your SWAP md0 mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /d........
  • CPanel Link to all of the command line options


    CPanel says you can access 98% of the functions through CLI which experienced Unix/Linux admins prefer for simplicity and for scripting.  I've never found CPanel easy to use from the admin panel, it seems everything is hard to find and a simple task becomes a series of hunts. So for people like me here's the list: http://cpanel.net/system-administrators/command-line-scrip........
  • Howto Convert Xen Image to KVM


    #count=10000 makes an image of 10000MB make sure your image is at least the same as your existing dd if=/dev/zero of=yourimage.img bs=1M count=10000 # losetup -fv newimage.raw # fdisk -cu /dev/loop0 # kpartx -a /dev/loop0 # dd if= of=/dev/mapper/loop0p1 # e2fsck -f /dev/mapper/loop0p1 # resize2fs /dev/mapper/loop0p1 # a lot of guides tell you to edit /etc/fst........
  • Migrate Linux Mint OS from one drive to another


    mount -o bind /proc /sda2/proc mount -o bind /dev/ /sda2/dev mount -o bind /sys /sda2/sys chroot /sda2 mint / # mount -o bind /proc /sda2/proc mint / # mount -o bind /dev/ /sda2/dev mint / # mount -o bind /sys /sda2/sys mint / # chroot /sda2 mint / # cd ~ mint ~ # ls Desktop mint ~ # cd / mint / # ls bin Desktop dev-temp home&nb........
  • pxe-32 tftp open timeout


    pxe-32 tftp open timeout The solution was to enable tftp in xinetd with "chkconfig tftp on". See the troubleshooting below: chkconfig --list NetworkManager 0:off 1:off 2:off 3:off 4:off 5:off 6:off acpid 0:off&n........
  • MySQL my.cnf Server How To Secure/Bind to Localhost and Prevent Outside Connections Solutions


    [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock user=mysql # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 bind-address=127.0.0.1 The key is "bind-address", set that to 127.0.0.1 and no one from outside the server can connect.........
  • SSH Can't Login/Hang


    Client Log OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008 debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to 192.168.1.253 [192.168.1.253] port 22. debug1: Connection established. debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1 debug1: identity file /root/.ssh/id_rsa type 1 debug1: identity file /root/.ssh/id_d........
  • Directadmin Log File Locations


    This is a handy link and list of all the relevant Directadmin log files and related servers. http://help.directadmin.com/item.php?id=11 DirectAdmin: /var/log/directadmin/error.log /var/log/directadmin/errortaskq.log /var/log/directadmin/system.log /var/log/directadmin/security.log Apache:........
  • kvm cannot boot xen guest using lvm


    This booting error is because the Xen PV guest image uses the Xen kernel, this is not compatible with anything but a host running a Xen kernel. I did a kpartx -av virtual.img and then it created some partitions that showed up in fdisk. I mounted it and did a chroot into it and removed the xen kernel and installed a normal kernel but Xen still shows the same kernel in Grub (only the Xen one). This is strange but it seems like this Xen PV guest has some sort of hidden or........
  • Apache Crash Solution Can't Restart Due to Socket In use - (98)Address already in use: make_sock: could not bind to address [::]:80 (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting d


    (98)Address already in use: make_sock: could not bind to address [::]:80 (98)Address already in use: make_sock: could not bind to address 0.0.0.0:80 no listening sockets available, shutting down This will even trip you up if you have a service like monit to save you if httpd crashes. The only way to fix this is to either wait (it's not an option for production situations) or to kill the ghost httpd processes that wouldn't gracefully close: So........
  • named/bind cannot find zone file, load zone files without specifying full directory path/loading master file genuine.com.zone: file not found


    genuine.com/IN: loading master file genuine.com.zone: file not found _default/genuine.com/IN: file not found I always found it silly that no one really talks about this and apparently many like me and even control panels like Plesk were still using hard paths. I always thought "why can't I just specify the name of the zone file and have bind find it". Surely the default search path must be /var/named or somewhere else but there is no such thing.........
  • Webmin/Virtualmin when enabling bind: Failed to save enabled features : Virtualmin is configured to setup DNS zones, but this system is not setup to use itself as a DNS server. Either add 127.0.0.1 to the list of DNS servers, or turn off the BIND fe


    Webmin/Virtualmin when enabling bind: Failed to save enabled features : Virtualmin is configured to setup DNS zones, but this system is not setup to use itself as a DNS server. Either add 127.0.0.1 to the list of DNS servers, or turn off the BIND feature on the module config page. It means what it says, add "127.0.0.1" to /etc/resolv.conf........
  • mdadm RAID 1 adventures


    I separated the 2 drives in the RAID 1 array. 1 is the old one /dev/sda and is out of date, while the separated other one /dev/sdc was in another drive and mounted and used with more data (updated). I wonder how mdadm will handle this: usb-storage: device scan complete md: md127 stopped. md: bind md: md127: raid array is not clean -- starting background reconstruction raid1: raid set md127 active with 1 out of 2 m........
  • Ubuntu 10.04/GRUB2 mdadm won't boot


    Moving to RAID was a pain. What you have to do is the following from an existing install: Install mdadm Create your mdadm RAID 1 array on your spare hard drive. Start it with the missing disk. rsync the entire contents of your current / to the md partition. Here's a good way of doing it: rsync -Pha --exclude=/proc/* --exclude=/sys/* --exclude=/mnt/* /. /mnt/md2........
  • How to chroot properly into your OS/distro


    From a LiveCD or if you're doing something like converting your non-RAID install to mdadm here's how you would chroot properly (you have to mount your proc, sys and dev on the running system/LiveCD to your chroot environment if you want things to work right, especially if you need to run update-initramfs due to a driver change etc..) *replace "path" with your mount/chroot path mount -o bind /proc /mnt/path/proc mount -o bind /dev/ mnt/pa........
  • sed script to automatically update IPs in named/BIND and httpd/Apache


    Always make a backup of the original file before trying this, I find this kind of thing when updating IPs etc.. to use a script. Where the old IP is "192.168.5.8" and the new IP is "10.10.5.8" sed -i s/192.168.5.8/10.10.5.8/g testdomain.org.db The -i with sed means "inline" meaning we edit the file directly, but without the -i we could just use >and output the results to another file or do whatever else we wanted.........
  • md: kicking non-fresh sda1 from array! - fix/solution


    md: Autodetecting RAID arrays. md: autorun ... md: considering sdb1 ... md: adding sdb1 ... md: adding sda1 ... md: created md0 md: bind md: bind md: running: md: kicking non-fresh sda1 from array! md: unbind md: export_rdev(sda1) raid1: raid set md0 active with 1 out of 2 mirrors The md0 raid kicked sda1 ou........
  • Linux Centos/RHEL can't find php/apache/httpd/mysql/ftp/exim/sendmail ?


    I wasted a lot of time wondering why I could never find those packages. Check the /etc/yum.conf file and at the bottom look for the "exclude=" line. Below is what I found in mine exclude=apache* httpd* mod_* mysql* MySQL* da_* *ftp* exim* sendmail* php* bind-chroot* Just remove those entries or uncomment that line and you'll get access to the missing applications.........
  • chroot into an off-line Linux version using a LiveCD/USB


    It's not just as simple as running the chroot command, you need to ensure the /proc and /dev entries are passed through and populated to the chroot environment. Step 1 - Mount Your Off-lineOS mount /dev/sda1 /mnt Step 2 - Mount Proc mount -t proc none /mnt/proc Step 3 - Mount Dev Most guides will tell you to use this: mount -o bind /dev /mnt//dev but that doesn't work for some reason in many cases: mount: wron........
  • Picking an FTPD (vsftpd) Server in Linux Centos/Debian


    I decided on using yum to help me decide even though I normaly use proftpd I decided to see what else I could find. yum search ftp Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * rpmforge: ftp-stud.fht-esslingen.de * base: mirrors.netdna.com * updates: updates.interworx.info * addons: yum.singlehop.com * extras: mirrors.netdna.com rpmforge........
  • Basic Port Listing


    Basic Port ListingHopefully someone finds this useful or at least interesting. http://www.sans.org/top20/#u9 Name Port Protocol Description Small services ........
  • OCFS2 crash


    When trying to even cd or ls the mounted OCFS2 partition it crashes. Ithink this is a combination of VMWare Server's problem and the way I mounted and symlinked to it. More than anything this shows the problem and lack of forsight with VMWare, but also that OCFS2 is easily crashed if you do strange things. Output of /var/log/messages for OCFS2 Apr 10 15:57:45 localhost kernel: [84331.691258] Modules linked in: vmnet vmci vmmon ocfs2_stac........
  • BIND/NAMED woes


    Feb 5 01:39:33 server named[19768]: zone myzone.com/IN: serial number (12331465) received from master 127.0.0.2#53 < ours (200901281) The above is taken from /var/log/messages This can be annoying, it can happen for a variety of reasons. What seems to be happening here is that the slave realizes the time on the slave is ahead of the master, so it therefore assumes it has the most up to date copy and won't actually transfer the zone. The solutio........
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